Cutting oil composition



CUTTING on. COMPOSITION N Drawing. Application November 25, 1953,

Serial No. 394,500 4 Claims. (Cl. 252-334) My invention relates to cutting oil compositions utilizing sulfur-chlorinated mineral oil as a base stock and particularly to the use of basic barium mahogany petroleum sulfonate to inhibit corrosion caused by such compositions.

Mineral oil compositions utilizing sulfur-chlorinated mineral oil as base stock arewidely used as cutting oils in metal-working processes. Such compositions stain copper black within a few minutes at room temperature andalthough they also stain ferrous metals black, such compositions are widely used as metal-Working lubricants for ferrous metals. In the working of ferrous metals with such compositions, it is advantageous to inhibit their corrosive action on the workpiece and on the slideways and other highly polished, exposed parts of the-machine tool.

I have found that the staining of ferrous metals caused by the corrosive action of cutting oil compositions utilizing sulfur-chlorinated mineral oil as base stock can be inhibited effectively by the addition of at least about 0.3 weight per cent of basic barium mahogany petroleum sulfonate to the composition. Moreover, I have found that basic barium mahogany sulfonate surprisingly is superior to other oil-soluble mahogany sulfonate soaps such as neutral barium or basic calcium soaps when compared either on the basis of the total sulfonate content or, for v the basic soaps, on the basis of reserve alkalinity. The basic barium sulfonate is effective at lower concentrations and for longer periods of time than neutral barium or basic calcium sulfonate. Surprisingly, the advantages of basic barium sulfonate are peculiar to it and do not reside By a basic barium mahogany petroleum sulfonate, I

mean a barium sulfonate derived from the oil-soluble or mahogany petroleum acids obtained by sulfuric acid, oleum or sulfur trioxide treatment of petroleum oils and containing barium hydroxide in excess of that required for neutralization of the acids. The basic barium mahogany sulfonate advantageously is prepared by treating a petroleum oil with oleum or sulfur trioxide, separating the sludge and neutralizing the oil-soluble mahogany acids, i. e. the acid oil, with ammonia, concentrating the resulting ammonium sulfonate by isopropyl alcohol treatment and converting the ammonium sulfonate to basic barium sulfonate by treatment with excess barium hydroxide. Alternatively, the basic barium sulfonate may be prepared by directly neutralizing a sludge-free acid oil with excess barium hydroxide.

By sulfur-chlorinated mineral oils, I mean lubricating oil fractions which have been reacted with sulfur chloride, e. g. sulfur monochloride. A preferred lubricating oil fraction has a viscosity of 100 Saybolt Universal seconds at 100 F. and a specific dispersion of at least 130, indicating aromatic or naphthenic character. Typical comnited States Patent ice mercial sulfur-chlorinated oils contain from about 2.5 to 3.5 per cent sulfur and from about 0.5 to 1.0 per cent According to my invention, 1 add basic barium mahogany sulfonate to a cutting oil composition utilizing sulfurchlorinated mineral oil as base stock in an amount of at a least about 0.3 Weight per cent based on the composition.

The corrosiveness of the sulfur-chlorinated mineral oil base is of such a nature that less than about 0.3 per cent of the sulfonate has little effect on its inhibition.

sulfonate based on the composition is suificient to inhibit the corrosive effect of 'the oil composition on ferrous.

metals. More sulfonate may be used but economic con siderations will generally preclude the use of more than about 0.6 per cent. in the form of a preparation containing various concentrations of the active ingredient, for example, at least' about 0.5 Weight per cent of a 60 per cent basic barium sulfonate concentrated preparation or at least about 2.0

per cent of a 15 per cent dilute preparation is added to the composition. The resuiting composition is substantially non-corrosive to ferrous metals and'can be used in metal working processes without undesirable staining of the metal piece being worked or the metal parts of the working machine. My invention will be further illustrated by reference to the following example in which the corrosiveness of sulfur-chlorinated mineral oils including such oils containing basic barium sulfonate, neutral barium sulfonate or basic calcium sulfonate was evaluated.

The tests were carried out on mild steel panels (A181 1018) which were surface ground on both sides, polished with steel wool and washed with pentane just before immersion in the test oil in a container. About half of. the panel was keptimmersed in the oil during the'test. When the panel was first put into the, oil, the container. was shaken so that the exposed surfaces of the panel were thoroughly wet with the test oil.

wetting and subsequent exposure to air and finally of reaction at the surface of the oil.

The action of the sulfonate in inhibiting staining and corrosiveness by the sulfur-chlorinated mineral oils manifests itself by markedly inhibiting initiation of staining of the steel panel and by retarding the rate of growth of a stained spot on the panel once it has formed. Both of these factors are taken into consideration in rating an inhibitor. With an uninhibited sulfur-chlorinated oil, the onset of staining occurs within about 24 hours after immersion of the panel depending on the nature of the base oil, the de ree of sulfur-chlorination and such random and fortuitous factors as microscopic cracks and pits in the test panel. Gnce a panel has been attacked in the absence of an inhibitor, the growth of the stain is rapid and in a matter of a few days the entire panel is stained black.

The basic barium sulfonate preparation used in the tests was prepared by subjecting a solvent-treated Mid- Continent oil, having a viscosity of 200 Saybolt Universal seconds at F. and a viscosity index of 85, to the action of five 25-pound portions of 25 per cent oleum per barrel of oil. After separation of the sludge, the

Patented June 21, 1955 petroleum oils,

Generally, about 0.3 to 0.6 weight per cent of basic barium The sulfonate conveniently is added Thus each test can'be used to evaluate the effects of prolonged immersion, of,

acid oil was blown with air to purge it of sulfur dioxide and neutralized with ammonia. The resulting ammonium sulfonate was concentrated by treatment with isopropanol and the concentrated ammonium sulfonate was converted toba'si'e barium sulfonate by treatment with an excess of barium hydroxide. The preparation contained 62.1 per cent basic ba-riumsulfonate, comprising 5 3 per cent barium sulfonate and 9.1 per cent barium hydroxide;

The neutral barium sulfonate preparation was prepared by treating a basic barium sulfonate with enough acid oil to neutralize the excessbasicity. Thebasic barium sulfonate was prepared by treating a raw Mid-Continent oil of- 200 Saybolt Universal seconds viscosity at 100 F. with oleum in the manner described above. The sludgefree and blown acidoil was neutralized directly with barium hydroxide to produce a preparation having a base number of 12 mg-ms. of KOH per gram and containing 15.8 pe'r cent basic barium sulfonate. On treatment with enough acid oil to neutralize the excess basicity, the

resulting neutral barium petroleum sulfonate contained 1.76 percent barium and 12.2 per cent barium sulfonate.

The basic calcium sulfonate preparation was prepared in the same manner as the basic barium sulfonate described above except that neutralization was carried out with. calcium hydroxide. The preparation contained 23.1 per: cent-basic calcium sulfonate, comprising 22.6 per cent calcium sulfonate and 0.5 3 per cent calcium hydroxide.

The percent inhibitor, i. e. basic barium, neutral bari-' um or. basic calcium sulfonate, used in the tests in this example refers to the weight per cent of gross preparation,v not the netconcentration of the active ingredient therein.

The. sulfur-chlorinatedmineral oil contained 3.03 per cent sulfur and 0.61 per cent chlorine and had an API gravity of 23.5, a viscosity in Saybolt Universal seconds of 140 at 100 F. and 41.5 at 210 F., and a pour point of 0 F.

When.thesulfur-chlorinated mineral oil containing no inhibitor was used in the test, the steel panel first showed a stain: after 24 hours and after days the panel was stained black-and peacock. When basic barium sulfonate was added to theabove oil in a concentration of 0.1 per cent,v the-first. stain appeared after 24 hours and after 30 days the panel showed somewhat lighter black and peacock stain than when no inhibitor was used. At a concentration of. 0.2. per cent, a stain did not appear until after. 3 days and after 30 days the panel was similar to the 0.1 per cent test. At a concentration of 0.3 per cent, a staindid notappear until after 3 days and after 30 days the panel. showed a rust colored stain. At a concentration of. 0.5 percent, however, a stain didnot appear for 27 days. and after 30 days the panel showed only scattered patches of light black tarnish.

When neutral barium sulfonate was added to the sulfurchlorinated mineral oil ina. concentration of 2.06 per cent, a. stain appeared on the panel after 3 days and after 30 days; the panelshowed a rust colored stain.

When basic calcium sulfonate was added to the sulfurchlorinated mineral oil in a concentration-of 1.0-5 per cent, the steel panel showed a stain after 3 days and after 30 days the panel showed a grayish-brown stain.

The results show that while at least about 0.5 per cent of the per cent basic barium sulfonate preparation was required to effect substantial inhibition of the corrosiveness of sulfur-chlorinated mineral oil, neutral barium sulfonate at a concentration of 2.06 per cent, which contributes the same sulfonate content as does 0.5 per cent of the basic barium preparation, was ineffective as an inhibitor and basic calcium sulfonate at a concentration of 1.05 per cent, which contributes the same sulfonate content as 0.5 per cent of the basic barium preparation and a basicity equivalent to 0.1 per cent of the basic barium preparation, was also inelfective as an inhibitor.

Thus, the results clearly show the etfective inhibiting action of basic barium sulfonate on the' corrosiveness of sulfur-chlorinated mineral oils. They also show the superiority of the basic barium sulfonate over either the neutral barium or basic calcium sulfonate and that the advantages of basic barium sulfonate as an inhibitor of sulfur-chlorinated mineral oils do not reside separately either in the barium sulfonate or the basicity of the excess alkaline earth hydroxide;

I claim:

1. Cutting oil compositions, consistingessentially" of a sulfur-chlorinated mineral oil base stock, to which has been added basic barium mahogany petroleum sulfonate in anamount of at least about 0.3 weight per cent based on the composition to inhibit corrosiveness.

2. Cutting oil compositions, consisting essentially of a sulfur-chlorinated mineral oil base stock, to which has been added basic barium mahogany petroleum sulfonate in an amount of about 0.3 to-0.6 weight per cent based on the composition to inhibit corrosiveness.

3. The method of inhibiting the corrosion of ferrous metals by cutting oil compositions consisting essentially of a sulfur-chlorinated mineral oil base stock which comprises adding to the cutting oil compositions basic barium mahogany petroleum sulfonate in an amount of at least about 0.3 weight per cent based on the composition.

4; The method of inhibiting the corrosion of ferrous metals by cutting oil compositions consisting essentially of a sulfur-chlorinated mineral oil base stock which comprises adding to the cutting oil compositions basic barium mahogany petroleum sulfonate in an amount of about 0.3 to 0.6 weight per cent based on the composition.

References (Zitedin the file of this patent UNITED STATES PATENTS 2,153,496 Berger et al. Apr. 4, 1939 2,268,608 McNulty et a1 Jan. 6, 1942 2,270,577 Bergstrom et al. Jan. 29 1942 2,511,250 Fawcett Jan. 13, 1950 

1. CUTTING OIL COMPOSITIONS, CONSISTING ESSENTIALLY OF A SULFUR-CHLORINATED MINERAL OIL BASE STOCK, TO WHICH HAS BEEN ADDED BASIC BARIUM MAHOGANY PETROLEUM SULFONATE IN AN AMOUNT OF AT LEAST ABOUT 0.3 WEIGHT PER CENT BASED ON THE COMPOSITION TO INHIBIT CORROSIVENESS. 